The inflatable volume of known gas bags is usually delimited by an exterior gas bag covering. In side gas bags, in particular in side gas bags which are stowed folded in a gas bag module arranged in the region of the roof edge of the vehicle, damage to its inflation orifice can occur during the filling of the gas bag, when the folded package is not pushed apart sufficiently quickly. The damage is due to the initially very high temperatures of the gas provided by a gas generator, and due to the high gas flow.